Engine light came in. Scan at auto parts store showed P0420, bank 1 catalytic converter. Is it worthwhile taking it to the dealer for diagnostics? Could be the O2 sensor or catalytic converter itself or something else I suppose.


If I need to replace the catalytic converter, does anyone have any recommendations for an after market one or universal one rather than paying through the nose for an OEM? How long do the original catalytic converters usually last?

 

I just replaced both my cats and all 4 o2 sensors went to 2/1/4 inch units made new pipes all the way under the car to the center muffler in 2/1/4 inch pipes then into the original middle resonator

Just picked it up last week sounds beautiful as my wife was driving the car back on the highway I drove next to her to listen if it was to loud its not and has a beefier note inside the car
I replaced the cats with 200 cell metal substrate units as cats are only good for 100,0000 k,s and my car has 167,000 k,s on the clock when I looked at the old cats they are starting to come apart on the inside

Car feels like its picked up some more power on the way but I also did new map sensor to be sure its all new with the o2 sensors cost was $1400 for all the pipework cats cost me $370 for the pair and the guy put the threads in them for the 02 sensors at the same time also had them all ceramic coated for heat reduction and longevity

I was planning to make a template of them to offer a custom set to other member's as a direct replacement but business commitments kept me busy so didn't go down that path

 

I had my battery disconnected for about 12 hours over the weekend while doing the coil strut conversion. The engine light was still on when I hooked back up. It stayed on for two days, and then this morning went off.

I had decided to try some cleaning formulas (Cataclean and a Lucas cleaner) and to clean the MAF sensor as a first step in troubleshooting. I think I'll still do that, but I'll be very happy if I don't need to replace the CC.

 

Just got this article on catalytic converters thought I would post it up

What Is A Catalytic Converter?
Image Courtesy of Master Muffler

The Catalytic Converter may not seem it, but it’s much more than a metal piece under your car. Hot exhaust gases exit your engine and head down the exhaust system to the cat. Inside this there is a honeycomb structure made from ceramic and different types of precious metals. This structure is coated with compounds that react with the expelled exhaust, and make it cleaner for the environment. Even though the exhaust gasses are pushed through the pipe at high speeds, the above mentioned compounds react to the gases within milliseconds turning the noxious gas to something less harmful like Carbon Dioxide and water vapour.
What Does A Catalytic Converter Do?
The cat reduces these gasses and cleans them into cleaner safer gases:

• Carbon Monoxide – Most used air leaving an engine is Carbon Monoxide, which is a deadly odourless gas. The cat creates a reaction between the CO and the surrounding air to create co2 and h2o.
• Hydrocarbons – VOC’s – Any compound made from carbon and hydrogen that can be burned. These are all made up of un-burned carbon and hydrogen.
• NOx – Most emissions failures have a high NOx reading. These are typically Nitrogen that is mixed with Oxygen that is expelled from the engine un-burned , creating smog etc.

How Does A Catalytic Converter Work?
The catalytic works in conjunction with your o2 sensors to clean the gasses. When everything is operating as it should and all the right parameters at set, I.E.: Air/Fuel, operating temp. etc., this should give you the cleanest possible exhaust. If you happen to have a faulty o2 sensor this can really start to have problems. The 02 sensor can alter your air/fuel mixture, and can possibly in the long run cause prematurely damage your Cat. Too lean of a mixture, and you will not have the right properties to clean the gas. Too rich and you could heat the cat up to the point of glowing red hot causing the internal structure to “melt” if you have a car that has the continual oil change (leaks like a siv) or leaks coolant into the engine, these issues can lead to a clog as it will coat the internals and not be able to expel the gas through the honeycombs. Keeping your car in top shape will help these to a minimum.
Once a cat reaches its optimal temperature roughly 400-600 degrees Fahrenheit the coated internals begin to do their job. There are three types of “harmful” emissions gasses that are regulated by the EPA. These are CO (Carbon Monoxide) Hydrocarbons- VOC’s (Volatile Organic Compounds) and NOX (Nitrogen Compounds). The compounds coating the innards of the cat remove most of the bad stuff and leave the expelled gasses much cleaner and safer.
What Are The Symptoms of A Bad Catalytic Converter?
A few signs of a cat actually being bad are as follows:

• Your vehicle’s fuel efficiency suddenly drops
• Your vehicle’s acceleration diminishes slightly
• Your vehicle may refuse to start or choke itself out
• The vehicle has Higher than normal emissions levels
• The cat itself starts to glow red
• Your vehicle produces a strong sulphur smell
• Rattling from the cat itself

Remember: When replacing any exhaust parts such as your catalytic converter it’s always a good idea to get the appropriate gaskets. I would also suggest replacing the pre and post oxygen sensors while you are there so you know your entire system is up to snuff. We offer a large selection of high quality exhaust for European cars.

Author: Bill Petrey

 

I'm running 100 cspi cats on the XJR with no issues at all
I did reset the adaptions wile installing the cats.

I also have minicats fitted, not sure if they are needed but have them anyway

Cheers
34by151

 

I guess I'm not so savvy with the terminology. 34by151, could you explain please how the cats you installed are different from OEM, where you got them (and cost), and what you did to reset the adaptations? Where are the minicats installed and, if you're not sure whether they're needed, why did you put them in? Thanks.

 

Ill point you a a couple of threads that have more info on my cats and pics of the install
Exhaust Manafold 4.2 S/C
https://www.jaguarforums.com/forum/x...upgrade-93043/

In short the XJR OEM cats are actually 2 cats in one box
The OS sensor is at the input then a 600 cspi cat
Behind this is the downstream o2 sensor and finally a 400 cspi cat

From memory the non S/C is 400+400 but both very restrictive none the less

The first plan was to go no cats at all
But looking at the fines

$15,000 for having no cats and $316 for excess emissions
So the plan changed to 100 cspi cats which offer very little difference to no cats at all

With that said the function of the downstream o2 sensor is to compare the gasses against the upstream sensor readings
IE it checks you have a cat and it working

To fool the sensor you can fit a cheepie unit
All this is is a tube pushing the sensor farther away
The theory is it get a smaller reading as it has less flow. This may or may not work for you and i think is a waste of time and money

A proper minicat has a mesh screen of cat material
So the gas passing though the tube actually pass a cat !!!
These are cheep and the link to bigdaddy's grrage that makes them is in the thread above.

The install is simple just screw them in where the sensor goes and screw the sensor in the other end

So in a nutshell the problem is when stock the downstream sensor is behind a 600 cspi cat. So any less and the margin to trigger an engine light is less

You may get way with 400, 200 or even 100 cspi cats but the mil waring get more and more sensitive as you are passing more gasses. Or to look at it another way the cat is less efficient sponge

So fitting a minicat brings the margin back. FYI if you run no cats fitting the minicat will prevent the error

btw I got my cats here 2 TWO X 2 25" 3" High Flow Metal SS304 Cats Catalytic Converters VT VX VU VY VZ | eBay

Cheers
34by151

 

Unless the catalytic converter has had physical damage or contamination, it should easily outlast the HO2 sensors.

Here is the full extract from the Jaguar DTC listing for P0420:



(click on the image to enlarge it)


The 'possible causes' are more likely to occur in reverse of the order shown.

With any emissions related error code, clearing and seeing if they repeat should be the initial approach before assuming the worst and immediately replacing parts. After all, the MIL is triggered by an out-of-range signal and this may just have peaked momentarily rather than being permanent.

After clearing P0420, the Efficiency Monitor Drive Cycle is the quickest way to check for a code repetition:

CATALYST EFFICIENCY MONITOR DRIVE CYCLE
1. Start engine and bring to normal operating temperature > 167 °F.
2. With the gear selector in Park or Neutral, hold the engine speed at 2500 rpm for 5 minutes.
3. Drive vehicle ensuring that vehicle speed exceeds 10 mph and engine speed exceeds 1500 rpm.
4. Stop the vehicle and check for any temporary DTCs.

At the end of this you could still have a permanent P0420 but will at least have satisfied yourself that expenditure on parts is absolutely necessary.

Graham

 

Thats why I used 200 Cell metal substrate the flow difference between the 100 and 200 was negligible but here in Australia the 100,s are illegal 200 just pass the sniffer test
Not that they are likely to emission test a jaguar but just to be on the safe side I went 200

 

kbeachy,

Have you looked into any universal cats? I did a quick search and these magna flow generic showed up a few places as fitting my 05 XJ8:
http://www.summitracing.com/parts/mp...FYpaMgodz24AMA

Frankly I've not looked at the exhaust in a while to see if they would even be close to fitting.(or if jag uses two sets of cats or what)...

Hmm, looking at the Gaudin parts it looks like it's part of the 'upper pipe' assembly and $1,200 and $1,400 per side. ?

Typical modern cats that fit close to the exhaust manifolds to warm up quickly.


It would certainly be worth looking into; find a good custom exhaust only shop and see if they can fit something universal.

 

I bought my cats seperatly had the o2 bungs welded in while he made them they cost 370 au for the pair of 200 cell metal substrate cats

I then took the car to a professional exhaust builder he then fabricated new pipes to the middle muffler with a Xpipe all done in 2 and quarter inch standard is 2 inch

I also had all the pipes ceramic coated the total cost 1300 au
You should be able to get something similar done where you are for same or less

Might pay to ask a few local exhaust shops what they could do the cat replacement for